The subject disclosure relates to a method and apparatus for tufting and particularly, to enable the production of a tufted product from a modified machine having many fewer parts than previously necessary.
In recent years the "Spanel Tufting System" involving multi-color tufting has been developed under the direction of Abram N. Spanel, a coinventor of the subject disclosure. Multi-color tufting has been a primary objective of the system with the purpose to enable the tufting of different color yarns for each tufting stroke. Under such a system, the production of detailed colored pictorials can be readily accomplished since yarn selection means can be included to choose a particular yarn from a plurality of yarn choices for each of the tufting strokes. With a "Spanel" tufting machine having on the order of 1200 needles, if there is a choice of, for example, five or eight colors for each needle stroke of the 1200 needles, it readily can be appreciated that a painting or other picture can be precisely and accurately reproduced in the form of a tufted product.
More precisely, the Spanel system utilizes pneumatic means to transport yarn to tufting stations, either in metered lengths of unsevered yarn or discrete yarn bits. The yarn is then tufted by needle or other bit-applying means to a backing layer to form a tufted product such as a rug.
Aspects of the Spanel system are disclosed in U.S. Pat. No. Re. 27,165 and U.S. Pat. No. 3,554,147, such as the concept and fundamental apparatus for selecting one of an array of yarn color strands and then transporting the yarn strand or a severed yarn bit to a needle station for tufting. A number of Spanel improvement patents disclose improved means of selecting yarn for the tufting stations. Basically, however, in the Spanel patents, regardless of the type of yarn selection system, yarn strands were metered by metering devices and fed pneumatically to a magazine or collator with multiple selection yarn tubes either leading directly to tufting stations or merging into a common passageway leading to the tufting stations. The metering device in the aforementioned U.S. Pat. No. 3,544,147 includes yarn brakes and yarn pullers which are individually actuated but which co-act to meter a length of yarn for yarn selection. Thus these Spanel patents disclose apparatus to select and meter a length of yarn for each of the needle stations.
For a full size "Spanel" tufting machine having on the order of 1200 needles, if there is to be a color selection of eight colors per needle then a total of 9600 cones of yarn are necessary with each having an independent yarn feeding and metering system. The tremendous cost and space requirements for such a machine are readily apparent.
As will fully be described herein, backing layer movement and control techniques have been developed to enable the elimination of a considerable number of needles, yarn cones, and yarn feeds by a factor as for example of eight. In effect, all apparatus concerned with handling yarn is reduced by a factor of eight while the overall dimension of the machine and the size of rug produced thereon remain the same.
Such a reduction in components is enabled in large measure by the ability to precisely control feeding of the backing layer as described herein. The backing layer of the subject disclosure is advanced and this advancement can be precisely controlled. In contrast, most conventional tufting operations utilize continuous feed of the backing layer which is not readily adjustable.
Additionally, backing movement control is disclosed herein which enables the lateral shifting of the backing layer. Backing shifters per se are well known in the carpet industry with the first ones being called "wavy-line" units. An eccentric wheel was used with an adjustable slot in the middle to enable adjustment of the shift to be made and once adjusted, the machine was permitted to keep running to produce what was known as wavy-line carpet. Such a procedure became well known with chenille bedspreads.
As disclosed herein, with programming and complete adjustability of the backing shifter, it will be appreciated by virtue of the backing feeding and backing shifting control, the precise location or placement of the needles into the backing layer is obtained.
Some of the improvements with the backing shifter of the subject disclosure can best be appreciated by viewing the use of backing shifters in conventional tufting machines. Conventional tufting machines, usually have needle plates placed below the needles with yarn being fed downwardly therethrough. In a conventional loop pile machine, the tuft hook is positioned below the needle plate. The backing flows over the top of the needle plates with backing fingers being used to support the backing and support the penetration load of the needles. Since the loops are continuous as they are formed on the face below the backing, it is not possible to effectuate the backing shift in the needle area because of the needle plate location. Accordingly, in a conventional tufting machine, the pin roll which is used is positioned at a distance permitting tangential engagements of the backing layer only. Thus, with the pin roll placed approximately two and a half inches from the needle location, it is necessary to move the backing approximately three-quarters of an inch to achieve a three-sixteenths inch movement at the needles. Thus is due to both the location of the pin rolls and the natural drag which is encountered because the loops are hooked onto the needle plate fingers in the proximity of the needle station.
As disclosed herein, since the pin roll is placed in close proximity to the needles, backing layer control very close to the needle station can be achieved. In view of this positioning of the pin roll, since there is no drag because of the nature of the tufting operation, it is geometrically predictable precisely how far the backing layer will move adding to the ability to precisely control a tufted product. Further, in the subject specification, the backing layer is moved in steps as distinguished from the conventional machine where the backing is in continuous motion creating a much higher drag factor.
With such control, it becomes feasible to laterally shift the backing layer in stepped manner with proper drive means so that a number of tufts such as eight can be tufted successively in a lateral direction by each needle. This in turn enables the removal of a considerable number of needles as alluded to previously and as will be fully discussed herein.